A small-animal activity-analysing system for behavioural studies

Automated recording and data analysis of the activity of small laboratory animals are often required for psychological and other forms of behavioural investigation. This paper describes such a system using an open field of 1·14×1·14 m. Three arrays of infrared-light-emitting diodes and phototransistors are used to locate the animal. Two of the arrays are used to generate an xy grid, while the third one is used to determine whether the animal is rearing. The position of the animal gives rise to both digital and analogue signals; so the equipment can be interfaced directly with a minicomputer, or coupled to an analogue recorder. Several activity parameters, such as the path length (absolute value of the line integral), the time spent at a predetermined area of the open field or the latency to move, are computed and displayed in digital form.     

An inexpensive means of indexing magnetic tape for the computer processing of analogue physiological records

The results of physiological experiments are often recorded as analogue signals on magnetic tape, and for computer analysis they need to be adequately marked. This paper describes a system for making digital marks on such records, as they are collected. Each mark is a 4-decimal digit sequence coded in binary form, providing a wide range of marking codes. Another system is described which detects these marks during replay of the record and passes the detected codes to a binary-register interface of a computer. The computer can use these signals to control the data processing and analysis of the record. The paper finally describes a system which detects the recorded markers during replay and displays the codes, in decimal form, on number indicator tubes. The systems are cheap and easy to construct and the marking device can conveniently be used with a portable instrumentation tape recorder.     

The real time video vector display of ground reaction forces during ambulation

A new radiotelemetry receiver type 7060 for use with radiopills is described. Its performance under laboratory conditions was assessed and its use for clinical colonic pressure measurements evaluated. The receiver, which resembles a small microcomputer, was easy to set up and worked reasonably well under ward conditions. Difficulties were experienced with the belt aerial supplied with the receiver, which did not reliably pick up signals from a freely moving radiopill. The receiver is not suitable for ambulatory applications. Its main clinical use is in situations where frequent sampling of the radiopill's signal over a long period of time is essential (e.g. colonic pressures). The large quantity of data generated can be fed from the receiver's analogue or digital output on line to a recorder.     

Superimposition of analogue data onto a video image: a new technique

There are many tools to aid the clinician in making an accurate medical diagnosis including various imaging techniques and recording analogue signals from the patient. A new, inexpensive method of combining a video image and the instantaneous values of analogue waveforms is described here. The system, TVDATA, is reliable, compact and portable and has been successfully used in various clinical situations. The unit requires a standard video source, such as a camera, a TV monitor, a video recorder and the output from the analogue source or sources. The analogue data are converted into a digital signal and then displayed in a convenient part of the screen as a horizontal bar. Two types of data channel are available—uni-and bidirectional. A number of these channels can be used to record different analogue parameters and an inbuilt octal frame counter assists subsequent review of the video record.     

Computerised method for acquisition and display of gastrointestinal motility data

A computerised system is developed for the acquisition and display of gastrointestinal motility data which utilises a purpose developed software program called ‘PC-motil’, running on an IBM compatible microcomputer. ‘PC-motil’ displays data during collection, writes data to disk file and compresses all data at the end of a study on to a single monitor screen for convenient overview. Any area of interest, in single or multiple channels, may be selected and expanded for detailed examination. This system is tested by the recording of gastric and jejunal motility patterns of 11 healthy volunteers in fasting and fed states. All antral and jejunal migrating motor complexes (MMCs) in fasting studies, as well as all fed motility patterns were recognisable in both ‘compressed’ and ‘expanded’ form. The reproduction of motility patterns by the computer based system was indistinguishable from that of a conventional analogue chart recorder. This computerised system provides a convenient and cost-effective means of acquisition, storage and display of motility data in digital form.     

Data acquisition of winterhardiness and temperature from living plants via telemetry

A data-acquisition system using telemetry is described for measuring physiological characteristics such as winterhardiness and temperature of plants. The electrodes and the thermocouples were inserted in the median portions of selected shoots of each plant. The analogue signals from the probes were converted into digital pulses, which modulate a transmitter. The probes were sequentially switched by a multiplexer to the analogue/digital convertor. The transmitted signals were received by a telemetry receiver, where the signals were demodulated, processed and recorded in analogue form, printed digitally or tape-punched for computer processing.     

Remote Control Systems' Radiotelemetry Receiver 7060: its use in clinical colonic motility measurement

A new radiotelemetry receiver type 7060 for use with radiopills is described. Its performance under laboratory conditions was assessed and its use for clinical colonic pressure measurements evaluated. The receiver, which resembles a small microcomputer, was easy to set up and worked reasonably well under ward conditions. Difficulties were experienced with the belt aerial supplied with the receiver, which did not reliably pick up signals from a freely moving radiopill. The receiver is not suitable for ambulatory applications. Its main clinical use is in situations where frequent sampling of the radiopill's signal over a long period of time is essential (e.g. colonic pressures). The large quantity of data generated can be fed from the receiver's analogue or digital output on line to a recorder.     

Analogue and digital instruments for non-invasive estimation of muscle fibre conduction velocity

Analogue and digital instruments for non-invasive on-line measurement of muscle fibre conduction velocity (CV) have been designed, built and compared using test signals and real myo-electric signals. Their inputs consist of two single-differential or double-differential myo-electric signals, obtained using a three- or fourcontact surface electrode system. The analogue device computes CV by tracking the lag of the zero-crossing of the cross-correlation between the first signal and the derivative of the second. The digital device computes the peak of the cross-correlation function between the two signals by sampling them at 50 KHz for 20 ms (or longer, up to 320 ms), computing CV in about 30 ms (or longer, up to about 670 ms) and resuming sampligg. Both devices allow estimation of CV during either voluntary or electrically elicited contractions and include a stimulation stage and a signal conditioner with artefact suppression features. Both devices provide analogue and numerical outputs and allow interfacing with analogue and digital instrumentation. They can be used in clinical or in research environments for easy and quick identification of appropriate electrode locations and/or for monitoring CV during sustained voluntary or electrically elicited contractions. The digital version is more versatile and requires no adjustments; it provides an estimate based on intermittent reading of the signals and is more sensitive to noise and momentary CV fluctuations.     

Measurement of Vmax of the cardiac action potential with a sample/hold peak detector

A simple device for measuring the maximum upstroke velocity (Vmax) of the cardiac action potential is described. It consists of a differentiator, filter, and sample/hold peak detector. The sample/hold cycles are automatically set by the stimulus. The circuit can drive a standard pen recorder and digital voltmeter, resulting in rapid and accurate measurements. An example of the effect of quinidine on the upstroke of the cardiac action potential is shown. The circuit can easily be adapted to other applications.     

Simultaneous recording of arterial blood pressure,heart rate and ST segment in the ambulant patient: a new system

A system developed for the accurate and simultaneous recording of blood pressure, heart rate and ST segment level in the unrestricted patient is described, with laboratory validation and experience of its clinical use. The recording system uses a brachial artery cannula, a transducer/perfusion unit and a miniature f.m.e.c.g. tape recorder (Oxford Medilog Mark II), one channel of which is modified to enable the recording of a blood pressure signal. Data are initially presented as analogue trend charts, with further detailed analysis being carried out by an automated digital system with interactive software enabling data editing and averaging. Laboratory evaluation demonstrated that the modified blood pressure channel had a satisfactory frequency response, linearity, signal-tonoise ratio, and temperature stability. Battery depletion produced a consistent increase in gain which could be compensated by repeated calibration throughout the period of recording. The system has been found to be reliable when used for recording periods of up to 24 h on patients with ischaemic heart disease.     

一种脑电效应计算机分析系统的设计及其应用

建立了一种新的用于记录和分析脑电信号计算机软硬件技术。首先通过模数转换技术将脑电的膜拟信号转换为数字信号，数字中直接存放于计算机硬盘，只要计算机硬盘允许可以长时间记录脑电信号，记录在计算机上的脑电信号可再进一步用于脑电效应分析，通过对用药后每秒脑电波数和脑电压的变化分析，采用１２－３０Ｈｚ之间每秒脑电波数或脑电压的变化可有效地反映受试者用药后的脑电效应变化情况，从而为进一步进行中枢神经系统药物的药     

Six-channel time-division multiplexed system for recording analogue data on the audio track of a videotape

A time-division multiplexer system employing a modified form of pulsewidth modulation to record six low-frequency analogue data on a single audio track of a videotape recorder is described. For each channel the data sampling rate is 200 per second, allowing an input data bandwidth of DC to 40 Hz. To obtain maximum signal-to-noise ratio with acceptably low adjacent-channel crosstalk, the recorded signal comprises narrow positive and negative pulses that correspond to the leading and trailing edges, respectively, of the width-modulated pulses. A demultiplexer/demodulator restores the original six low-frequency analogue signals by developing the train of width-modulated pulses from the signal replayed from tape, separating them and passing them to individual demodulators. For each output channel, frequency response is 0–40 Hz, overall linearity is within±1 per cent and peak-to-peak noise and adjacent-channel crosstalk amount to less than 1 per cent of maximum peak-to-peak output. Tape speed fluctuations have little effect on baseline but cause small variations in demodulator sensitivity. These effects of tape speed fluctuations can be eliminated completely using an alternative demodulator that requires output bandwidth to be limited to 0–25 Hz.     

A b.c.d. encoder for the indexing of analogue tape recordings

Circuit details are provided of a simple device which allows the marking of analogue tape recordings with a binary-coded-decimal (b.c.d.) representation of a 3-digit decimal numeral. The code produced may be replayed on a chart recorder, and can easily be decoded by eye.     

3-lead electrocardiogram transmission over Post Office telephone lines

A 3-channel analogue f.d.m./f.m. system for the transmission of 3-lead e.c.g.s over Post Office telephone lines has been developed following technical and economic considerations of both analogue and digital techniques. This system is used in conjunction with a low-speed digital telephone link to enable e.c.g.s from an outlying hospital to be transmitted to a central computer and analysed. The overall system has been in routine operation for over 17 months and has, with the exception of occasional interference from line-impulse noise, proved an effective method of reporting e.c.g.s from outlying hospitals.     

The efficacy of ribamidil in experimental RS-virus infection]

The antiviral activity of a national analogue of virasol, ribamydil, with regard to RS virus infection was studied in tissue culture and in experimental animals. In L-41 cell cultures ribamydil in a dose of 60 micrograms/ml or more completely inhibited multiplication of RS virus strain Long, in a titre of 4.75 lg CPD50. The drug concentrations of 30, 15, and 7 micrograms/ml reduced the virus content by 3.75, 2.75 and 2.0 lg CPD50, respectively; ED50 of the drug was 7 micrograms/ml, the chemotherapeutic index was 71. In cotton rats, RS virus infection could be reproduced in 95%. Subcutaneous inoculation of the injection form of ribamydil in a dose of 100 mg/kg body weight prevented the development of infection with RS virus in 100% of the animals.     

数字式多道生理信号示波器的研制

目的研制数字式多道生理信号示波器。方法仪器采用PC机外挂采集盒的方式,386以上的PC机即可,仪器结构简单灵活。采用虚拟仪器设计技术,操作界面更加友好。结果此示波器具有实时测量、分析、显示、存储、打印等功能。结论此数字式多道生理信号示波器可替代日前教学和科研中使用的模拟生理信号示波器及其它生理信号记录装置,对教学和科研有一定的促进作用。该仪器具有很高的性能价格比,可大量推广使用,有望取得较好的社会、经济效益。     

心音包迹标测图的临床应用——附124例报告

心音包迹标测图是运用自行研制的专用记录仪，在受检者胸前３０个标测点分期同步录制的心音包迹图，以阵列方式把３０个心音包迹图显示在一张图上，经６０例正常心音受检者和６４例有心音异常患者的初步应用，并与同期所作的普通心音图进行对比研究，结果表明：（１）ＨＳＥＣＭ具有形象直观，信息丰富，能按实测方位全面地展示胸前３０个部位的心音包迹形态，并构成一幅心音音场态势图；（２）便于对各标测部位的心音形态进行对比研     

一种微型低功耗生物遥测双向射频通讯系统

介绍了一种微型、低功耗双向短距离射频通讯系统,此系统可用于植入式或口服式生物遥测装置.此系统由位于体内的微型射频收发器和体外的数据存储器组成,系统所用的通讯频率位于ISM波段,微型收发器与数据存储器之间使用半双工方式通讯,使用FSK调制方式实现了双向数字通讯.此系统体积小、功耗低、接口简单,可直接与单片机连接,便于组成各种短距离生物遥测系统.我们利用此系统组成一种口服式人体消化道生理参数检测装置,并对此装置进行了初步的动物实验.     

Analogue counter integrator for brain-cell unit activity counting

A low cost analogue counter integrator was developed using 4 transistors and 2 integrated amplifiers. It is used for brain-cell unit counting and rate measurements. The output signal may be transferred to a paper recorder. The system is specially useful for the long-term rate recording of unit activity and can be used for transient drug effect evaluation. The integrator output includes information on the average rate without losing the timing of each cellular action potential.     

Automatic read-out device for ultraviolet-radiation polymer-film dosimeters

An automatic device for measuring the optical absorbance of polymer film used as an ultravioletradiation dosimeter is described. The automated mechanics are based on a commercial slide projector. The ultraviolet radiation is generated by a tungsten quartz-halogen bulb. The optical absorbance is determined by analogue logarithmic circuitry and the resultant value displayed on a digital panel meter. A digital printer or paper-tape punch may be used for hard-copy output. An uncertainty in measurement of 1% is obtained. The device temperature stability is such that this uncertainty can be maintained for analogue circuit temperatures of 20–40°C.